Musannaf Ibn Abi Shayba 3:3833

Waki’ narrated to us, he said: Al-Rabi’ ibn Sabih informed us, he said: Someone who saw Umar ibn Abd al-Aziz praying in a *jubba* (outer garment) of *tayalisa* (a type of shawl or cloak) informed me, while he had no *izar* (lower garment) on him.